The present disclosure relates generally to information handling systems (IHSs), and more particularly to IHS snoop filter optimization.
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system (IHS). An IHS generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements may vary between different applications, IHSs may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in IHSs allow for IHSs to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, IHSs may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
IHS server and workstation chipsets use snoop-filter caches (SF Caches) to reduce the percentage of cache line snoops on a remote bus, to improve performance. The snoop filter cache stores a directory of all processor cache lines to minimize snoop traffic on the dual front-side buses during a cache miss.
In theory, a snoop filter ensures that snoop requests for cache lines go to the appropriate processor bus (e.g., on a system with multiple front side busses (FSBs)) and not all of the available busses, thereby improving performance. Therefore, applications will benefit from a reduced snoop activity that the snoop filter cache provides.
Experiments have shown that a snoop filter does not improve performance for all applications, and moreover its performance impact is sensitive to the system configuration. In many cases, the snoop filter can cause performance degradation for certain workloads.
Accordingly, it would be desirable to provide a static and dynamic optimization of a snoop filter to optimize performance of systems with a snoop filter cache, absent the deficiencies described above.